Lathe-chuck



(NoModeL) J.'N. SKINNER.

LATHE OHUGK. N0. 303,331. Patented Aug. 12, 1884.

77 iinea'aeo'. fnven/ ron N. PETER5. mam-1 m. wmm um ma .UNITED STATESPATENT OFFICE.

JAMES N. SKINNER, OF NEW BRITAIN, CONN EOTIOUT.

LATHE-CHUCK.

SPECIFICATION forming part of Letters Patent No. 303,331, dated August12, 1884.

Application filed May 17, 1883. (No model.)

- whereby a person skilled in the art can make and use the same,reference being had to the accompanying drawings, and to the letters ofreference marked thereon.

Like letters in the figures indicate the same parts.

Figure l is a face view of a three-jaw chuck of my improvedconstruction. Fig. 2 is a view in cross-section of same on plane denotedbyline as a: of Fig. 1. Fig. 3 is a detail side view of a jaw withholding-faces reversed. Fig. 4 is a view in section on plane denoted byline y y of Fig. 8. I

My invention relates to the ordinary and well-known form oflathe'chucks; and it consists in the special combination of parts forholding the body-halves together.

In the accompanying drawings, the letter a denotes one body-half; b, theother bodyhalf; 0, the jaw as a whole; d, the threaded shaft bearing thepinion 6, adapted to mesh into the ring-gear in the usual manner forchanging the chuck from the independent to the combination form, or thereverse.' Into the central opening, through the body-halves, the hollowbolt or sleeve f is fitted, screwthreaded to secure it in the threadedsocket, and having the flanged head f fitting in the countersunk seat I)in the body-half. Mortises g g or similar devices are provided asholding-places for a tool'used in screwing the bolt into or out of itssocket. This hollow bolt is especially serviceable in closing, as itdoes, the opening between the body-halves heretofore left at the sidesof the central open ing through the chuck. The jaw c is divided into twoparts on a line in the direction of its length; and these parts may becalled the nut-section h, as it bears the nut through which the shaft (1operates, and the holdingsection z. The holding-section 2' restsdirectly upon the face of the chuck, and has along its length andopening downward the T-shaped mortise. The nut-section h is adapted tobe moved within the body of the chuck by means of the shaft (1, whichfits the threaded socket of the nut-section, and it has a T-shapedtenon, which passes through the usual slot in the face of thechuck-body, and fits into the mortise in the holding-section i. Thesejawsections, when ready for use, are held together by means of thetapered screws, as shown in Fig. 2, and when so assembled the frontbodypart of the chuck, at the edges of the radial slots, fits into thegrooves (see Figs. 3 and 4.) left between the jaw-sections. When thejaws are holding any piece of work, the section'i bears against theoutside of front body-half and the nutsection against the inside, andany play or looseness of parts caused by wear I can be taken up byshaving off the upper surface of the tenon and drawing the jaw-sectionstogether with the tapering screws.

The holding-section is provided with the usual serrated or roughenedholding-faces, l, on one or more steps, and these faces are concaved atabout the center Z, and chamfered at the edges Z, so that they areadapted to hold either a convex or a concave object. One specialadvantage of this feature in this regardv is that the chuck, with theparts, as shown in Figs. 1 and 2, adapted to grasp the outside of anyobject, may be readily changed to grasp the inner surface of a hollowcylinder or the like by simply removing the screws, turning theholding-section end for end, (see Fig. 3,) and replacing and turninghome the screws. In the latter position the grooved holding-face 11gives a long bearing and a firm hold for using a drill or the like.

The openings at through the chuck are for the purpose of holding thedog, to prevent work from rotating in the grasp of the chuck.

The flanged hollow bolt not only serves to exclude dirt from theinterior of the chuckbody; but it also serves a more important purposein binding the body -halves firmly to gether at the center.

\Vhen the jaws are used at the outer limit of their play in holding anobject, the strain often springs up and breaks the body-half a, when thebody-halves are united in the ordinary way.

I claim as my invention- In a lathe-chuck, in combination, thebodyhalves bearing the countersunk and threaded sockets, and the flangedhollow bolt, all sub stantially as described.

Witnesses: JAMES N. SKIN N ER.

CHAS. L. BURDETT, EDWIN F. VDIMOOK.

